We propose to use molecular virological, immunological and genetic techniques to develop and study new vaccines and antiviral approaches. Individual projects involve: (1) the development of chimeric and bifunctional immunoglobulins to enhance and stimulate the host's immunity against influenza virus and HIV infected cells; (2) the exploration of the antisense RNA concept and the principle of ribozyme inhibition in tissue culture cells and in transgenic mice using influenza virus and retroviruses as models; (3) the development of influenza virus vaccines and vaccine vectors based on the ability to use recombinant cDNA techniques to engineer influenza viruses; and (4) the study of antisense oligonucleotides.